Should You Be Concerned About the Zika Virus?

Most of what is known about the mosquito-borne Zika virus comes from its explosive spread in Central and South America. The Philadelphia region is different.

Who should be worried?

For now, public health officials say they are mainly concerned about pregnant women who recently traveled to any of the affected countries. A small number of cases there have been linked to birth defects. Women who are pregnant have been advised to postpone travel to those areas. Pregnant women who recently returned from infected areas should consult their health-care provider.

Could the mosquitoes responsible come here?

The species that caused the epidemic in the tropics, Aedes aegypti, does not live near Philadelphia.

Could other species spread it?

Aedes albopictus, which is common locally, is theoretically able to carry the virus, but there are no known examples outside of laboratory conditions. If it does, then the virus could spread locally.

Whether albopictus, the Asian tiger mosquito, would be an efficient vector - able to easily transmit the virus from one animal to another when it feeds on blood - is unknown.

Could the virus mutate?

A mutation that allows Zika to be carried by other mosquito species is possible. The likelihood is unknown.

Could it be transmitted in other ways?

Widespread person-to-person transmission is very unlikely. Viruses like dengue, which has been carried by the same mosquitoes for years, are not passed from one human to another.

Transmission via blood transfusion and sexual contact have been reported but not confirmed.

What are the symptoms?

They are similar to the flu, although Zika typically is milder. Four out of five infections cause no symptoms at all.

How can I protect myself from Zika?

Unlike many developing countries, the United States has established mosquito-eradication programs; most houses have window screens; and many homes and workplaces are air-conditioned.

If Zika arrives in the region, expect public-health officials to give the same antimosquito guidance that they do for West Nile virus, only louder: Get rid of standing water, where the insects lay their eggs: birdbaths, old tires, cans, gutters. Repair broken screens. Wear long pants and shirts when mosquitoes are active, and use insecticide containing DEET.

What's the big deal?

Residents of the Americas do not have immunity to the virus. Birth defects as well as temporary paralysis in adults are rare but serious. Perhaps the biggest concern is that so much about Zika is unknown.

- Don Sapatkin

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